That's pretty much my thoughts. A cop with a light is going into a strange place and has to see where he's going, I don't. I'm at home and know every inch by heart. In a hide and seek situation whoever gives away their position by turning on a light first loses.
Assuming there was something that made you investigate in the first place - most folks don't wake from a sound sleep and decide to do an armed search of their house for no reason, although I'm sure at least one or two here do.
Anyway, something alerted you. I figure it's best to sit tight and wait, ambush them if they become a threat. Or if you simply have to take a proactive stance, creep silently, stalk them in the darkness since you have the home field advantage. You know that they, or something, is out there - they don't know you've been alerted unless you do something to let them know.
Everybody will have a different take on this, but my job is to protect my life first and property second. If you hear them carting off your refrigerator and unbolting the doors, okay, they are occupied and you can go get'em. But I'm not particularly eager to go on a house clearing mission - I'll wait and blow them away from hiding if they get far enough in the house to present themselves as an immediate threat to me.
On a different note - the best burglar reactive defense I have heard of is a guy who wired several lights in his house into one switch just beside his bed. If he heard a noise or was alerted, he just flipped the switch and the living room and other places lit up. If someone was inside they immediately knew they were discovered and hopefully would vamoose, but if he had to go on a search and destroy mission he could stay in the darker areas and see out into the lighted areas.
Avoidance first, confrontation second. And if you must confront, tactics should be designed to give the other guy NO chance at all and stack the odds in your favor every way you possibly can.
